Process of operating ore-concentrating tables.



E. -B. KIRBY.

PROCESS OF OPERATING ORE CONGENTRATING TABLES.

APPLICATION FILED JULY 1, 1910.

1,1 05,799. Patented Au 4, 1914.

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THE NORRIS PETERS CO, PHDTO-LITHO. WASHINGTO Dr C UNIJTED STATES PATENTOFFICE.

EDMUND B. KIRBY, OFST. LOUIS, MISSOURI v PROCESS OFOPERATINGORE-CONGENTRATINGTABLES.

Specification of Letters Patent.

Application filed July 1, 1910. Serial No. 569,945.

Patented Aug. 4, 1914.

To all whom it may concern.

Be it known that I, EDMUND B. KLRBY, a citizen of the United States,residing at St.

.Louis,in theState of Missouri, have invented a certain new and usefulImprovement in Processes of Operating Ore-Concentrating Tables, ofwhichthe following is a full, clear, and exactdescription,

This, invention is a new method of convarieties (the well known Wilfleytable be ing an example) the; differentialvibration of the table in onedirection, and the flow of water across the table in a relativelytransverse .direction, cause the grading of the pulverized ore thereon,and the arrangement of the various grades in bands of which the frontband includes theheaviestland most valuable mineral constituent of theore. These bands extend and slowly move in a generally diagonaldirection, which. is the resultant of the two forces (viz. the differential vibration of the table and the force of the water) which causesuch arrangement andflow. It has long been a matter of commonknowledgethat these bands of the difierent grades of the ore overlapeach other,-the rear edge of each band being overlapped more or less by.the front edge of the next band behind it. It has also long been knownthat the lapping parts of these bands are imperfectly graded. Theseconditions and the attendant disadvantages and resulting losses, have,however, heretofore been assumed to be the incurableresults of theoperation of such tables.

In association with the concentrating tables, means have heretofore beenemployed to split the bands for the purpose of recovering separately thedifferent grades which have been formed and arranged as stated;Sometimes several grades are recovered, but heretofore either with loss,or else the grades are not entirely separated from each other. Sometimesit is only the heavy "mineral in the front band that is to be recovered.For the purpose of comparing the invention whichthis patent covers withthe prior practice, it may be asof which there are many tice, becausesurned that it is only the front band which contains valuable mineralwhich it is desired to recover. The band splitting means heretoforeemployed have generaly been in the form of some kind of adjustabledividingedge such as a bladeadjustable on the table, at the delivery endthereof; and

this blade has been placed so as to cut off and segregate the whole orsome part of the front band as the material passes off the table. Themost general practice isto place said splitting device so that,,asnearly as possible, it will. split the front band along the surface lineor division between it. and

the next band. To the extent which this can be done, practically, thematerial which is split off and recovered is very nearly pure, butobviously there is lost all of the material of the front band which isoverlapped by the nextband, orwhich is imperfectly separated from thematerial of the next. band.

Of course, if one desired to recover all of the valuable mineralbelonging in the front band, the splittingofl blade could. be adjustedso that, as nearly as possible, it will split the front band in the lineof the rear edge of the underlapping part thereof.

This [very clearly would recover nearly all the valuable materialbelonging to the front band, but mixed with it will be all of the lessvaluable material which overlaps and is partly blended writ-h the rearpart of the front band; Again, one may compromise between these twopositions, and seekto split the band somewhat intermediate of the rearedge of the front band and thefront edge of the next band. But in anyevent, the separation ofthe bands is, as stated, effected at ornear thedelivery end of the table. None of these or the other adjustment beattempted will adjustments are ideal; and whether the one depend uponcircumstances, although, gen

erally speaking, the first adjustment re ferred to is that which is mostcommonly sought for; None of these adjustments can, however,beaccurately maintained in pracbackand forth on the table, so that,"if thesplitting device be accurately adjusted for the, then existingconditionsto secure whatever result is desired, the positions of the bands might,and generally do, in thenext.

the bands actually fluctuate few minutes, so change that these delsir'edresults would not :be secured? Any gvarias 'tion in the force or volume'of the water used, or any variation inthe force ofthe;

be repeated as often as desired. They may the .front edge of the frontband be'cut ofl jerk of the table, and some other causes which are knownand need not be specified, produce always, in practice, these smallfluctuations of the. moving bands forward and backward upon the tabletop.- My method of operation, however, i'ssuch that small fluctuationsof the band do not much affect its successful operation, nor prevent therecovery of substantially all of, the valui-v 10- able mineral in tialpurity. v My method consists in splitting off and the front band,',insubstanremoving the front edge of the front band+ any part of it, backto the surface line of division between it and the next band be fore themoving bands" reach the end of the table, so that. what remains will besub-, jected to the combined influence of the dif-' ferential vibrationand the water. flowing acrossthe. table. The material so split off" andremoved had, before its removal, served as a barrier which prevented'thewash water fromactingupon and grading the, lapping .parts' of the twobands and these shielded 25 wash water, with the result that very soonthe. greater part of these overlapping strata parts are now exposed tothe action of the are graded and. a newfront band .of the heavy valuablemineral created. It may be i that some .part ofthe rear edge of thisnewly formed front band is. overlapped by 4 thenext hand. If this is so,and if thequana V tity so overlapped makes it desirable, the front part.of'this newly formed bandmay :be, again. split off. andremoved, andsuchof the material as remains again be subjected to'the influence ofthe water and the jerking of the table.- In fac t,-.these operations mayevenbe repeated enough times to recover in substantial purity two ormore, grades of mineral, if there be more than one band ofinaterialwhich it is desired .to recover; forfl'afterthe materialoriginally in the front bandis'all recovered, the next band may betreated in the same way, beforethe end of the table is reached. In anyevent, whether more than once'for regrading, a very large part. of thehigh grade mineral whichwas at first overlapped byor mixed with thematerial properly belonging in the nextband will be. saved and recoveredinsubstantial purity; and the described operations may ,be. repeateduntil. the high grade material V which remains-is an inconsiderablefraction I It is obvious that small fluctuations of the bands back andforthon the table do not 60.,

necessarily interfere with the successful operation. of the process. Thecutting off means may be placed'so that the fluctuation of the. bands"will. only result in increasing or decrefising-thewidthof the strip ofpure through the table; band "of the heavy "mineral constituents ofmineral which is removed. This may or may not vary the fraction of thishigh grade ore which is finally recovered; but in any event, theunrecovered "fraction wlll always:

be small, and the percentage of pure high grade mineral recovered willbe very large, by comparison with the results obtained by the methods"of operating concentrating tables heretofore practised.

In the drawing Figure 1 isa 'showing,.more or less conventionally, a concentrating tableladapted for the purpose of this invention. Themeans'for vibrating the.

plan view table, are not shown,.. nor are the means for I dischargingthe wash waterionto the table.

These ineans,'fhow'ever, arewell'knownin the art and are essentiallywell known features of practical concentrating tables, and

it is to be understood that whatever variety of concentrating table beemployed, they" should "be provided with these invariably present parts.Fig. 2 is a sectional view on the plane of line F G on Fig. 1. Fig.3is'a sectional'view on the plane of l'ineI-I*I on s and Fig. 4: is asectional view on the plane of'line J'+-'K on Fig. 1. J

Referring to the parts by reference letters, Agrepresents. theconcentratingftable which is slightly inclined downward fr'om front torear, and a, a represent slots 6 represents the front the ore, and 0represents the band of the next grade, which we maycall Ethe mid-f'dlings, and drepresents what may be called the tailings. These bands,as they'appear at. the leftend' of said Fig. 2 are, as they areoriginally formed, the overlap of-the rear edge. of the: front band bythe next band he a hind. it being clearly shown. This slot a isso'placed' that a greater orlesspart of the front band 6 will pass overit and will 'drop th'rough it, these'slots 'being.a convenient methodofsplitting off and removi' ing the frontedge of'lthe front. band. The

remainder. of the materials pass behind this slot and How toward thedelivery end of the. .table in the diagonal direction shown, and. theuncovered front part ofthe materialissubjected to the action of the washwater, whereby it will be regraded' and rebanded.

That is to say, anewflfront band b' of the. heavy mineralqwill beformed. The slot a p is so'placed that mor'eor less ofthe'unlappedc'part of this newfrontba-nd b" will pass over include only a veryinconsiderable fraction of all of the high grade mineral which thepulverized ore origlnally contained.

Having thus described my invention, what I claim is:

1. The hereindescribecl process of jconcentrating ores which consists indelivering the ore in a pulverized condition onto aconcentrating table,in imparting to said table a differential vibration, and insimultaneously discharging a forceful sheet of wash water crosswise ofthe table in a direction transverse to the direction of the vibration,whereby said pulverized ore is arranged in bands and caused to travelalong the table in a direction which is the resultant of the two statedforces, in removing the front portion of the front band of material atsuch a distance back from the discharge end of the table that theremaining material before it reaches said discharge end will be rebandedby the combined action of said wash water and differential vibration.

QLThe herein described process of corn centrating ores which consists indelivering the ore in a pulverized conditiononto a concentrating table,in imparting to said table a differential vibration, and insimultaneously discharging a forceful sheet of wash water crosswise ofthe table in a direction transverse to the direction of the vibration,

whereby said pulverized ore is arranged in bands and caused to travelacross the table in a direction whichl is the resultant of the twostated forces, in removing the front portion of the front band ofmaterial at such a distance back from the discharge end of the tablethat the remaining material will be re banded before it reaches saiddischarge end by the combined action of said washlwater and differentialvibration, and in repeating as often as may be required, this removal ofthe front partof the front band,land sub? sequent subjection of thematerial to the com? bined actionof the differential vibration of thetable and the forceful sheet of Wash ess consisting in removing a largepart of the non-overlapping front edge of the front band of said ore ata point on the table such that the remaining ore will be rebanded beforeit reaches the discharge edge of said table, and in subsequentlysegregating from p the rebanded ore a greater part of the n0noverlappingfront edge of the newly formed front band.

In testimony whereof, I hereunto affix my signature in the presence oftwo witnesses.

EDMUND B. KIRBY.

Witnesses:

W; Tl HICKMAN, MARIE S. COLCORD.

Copiesotthis patent may be obtained for .flve cents each, by addressingthe Commissioner of Patents, Washington, D. 0.?

a result of the two stated forces,said proca

